Which Tanner stage is associated with adult-like hair starting to extend across the pubis?

The Tanner stages, also known as the Sexual maturity rating, are used to assess the development of secondary sexual characteristics during puberty in both boys and girls. In the context of pubic hair development, Tanner Stage III is characterized by the development of coarser and darker pubic hair that begins to spread laterally across the pubis, resembling an adult pattern, although it is not fully matured yet.

At Tanner Stage I, there is no pubic hair present, as this stage represents pre-pubertal development. Tanner Stage II introduces the initial growth of fine, downy hair that is spread over the labia (in females) or at the base of the penis (in males). By Tanner Stage III, the hair becomes denser and the distribution starts to mirror what is observed in adults but without fully extending across the pubic area as seen in later stages. In Tanner Stage IV, the hair is further developed, becoming adult-like and more spread out, reaching even more toward the inner thighs.

Therefore, the correct association of Tanner Stage III with adult-like hair beginning to extend across the pubis aligns with the typical descriptions utilized in understanding pubertal development.